_Fragmenta philosophorum Graecorum_, i.
(1860); F. Panzerbieter, _Diogenes Apolloniates_ (1830), with
philosophical dissertation; J. Burnet, _Early Greek Philosophy_
(1892); H. Ritter and L. Preller, _Historia philosophiae_ (4th ed.,
1869), SS 59-68; E. Krause, _Diogenes von Apollonia_ (1909). See
IONIAN SCHOOL.

DIOGENES LAERTIUS (or LAERTIUS DIOGENES), the biographer of the Greek
philosophers, is supposed by some to have received his surname from the
town of Laerte in Cilicia, and by others from the Roman family of the
Laertii. Of the circumstances of his life we know nothing. He must have
lived after Sextus Empiricus (c. A.D. 200), whom he mentions, and
before Stephanus of Byzantium (c. A.D. 500), who quotes him. It is
probable that he flourished during the reign of Alexander Severus (A.D.
222-235) and his successors. His own opinions are equally uncertain. By
some he was regarded as a Christian; but it seems more probable that he
was an Epicurean. The work by which he is known professes to give an
account of the lives and sayings of the Greek philosophers. Although it
is at best an uncritical and unphilosophical compilation, its value, as
giving us an insight into the private life of the Greek sages, justly
led Montaigne to exclaim that he wished that instead of one Laertius
there had been a dozen. He treats his subject in two divisions which he
describes as the Ionian and the Italian schools; the division is quite
unscientific. The biographies of the former begin with Anaximander, and
end with Clitomachus, Theophrastus and Chrysippus; the latter begins
with Pythagoras, and ends with Epicurus. The Socratic school, with its
various branches, is classed with the Ionic; while the Eleatics and
sceptics are treated under the Italic. The whole of the last book is
devoted to Epicurus, and contains three most interesting letters
addressed to Herodotus, Pythocles and Menoeceus. His chief authorities
were Diocles of Magnesia's _Cursory Notice_ ([Greek: Epidrome]) _of
Philosophers_ and Favorinus's _Miscellaneous History_ and _Memoirs_.
From the statements of Burlaeus (Walter Burley, a 14th-century monk) in
his _De vita et moribus philosophorum_ the text of Diogenes seems to
have been much fuller than that which we now possess. In addition to the
_Lives_, Diogenes was the author of a work in verse on famous men, in
various metres.

BIBLIOGRAPHY.--_Editio princeps_ (1533); H. Hubner and C. Jacobitz
with co